Husband has dementia. Last night he slept from 10 pm until 2:30 pm this afternoon. Then wanted to go back to sleep. Should I keep him awake?

When this happens is it better to let him sleep or try to keep him awake? When he is awake he will close curtains and shut off all the lights. If I say we will go out he will stay awake. Wondering what to do. I worry if this continues whether he will just not wake up. I usually take him for walk in transfer chair at park or mall but now it’s getting colder and more people are in the mall so I worry about COVID-19.